1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Functions related to setting various queue properties from drivers 4 */ 5 #include <linux/kernel.h> 6 #include <linux/module.h> 7 #include <linux/init.h> 8 #include <linux/bio.h> 9 #include <linux/blk-integrity.h> 10 #include <linux/pagemap.h> 11 #include <linux/backing-dev-defs.h> 12 #include <linux/gcd.h> 13 #include <linux/lcm.h> 14 #include <linux/jiffies.h> 15 #include <linux/gfp.h> 16 #include <linux/dma-mapping.h> 17 #include <linux/t10-pi.h> 18 #include <linux/crc64.h> 19 20 #include "blk.h" 21 #include "blk-rq-qos.h" 22 #include "blk-wbt.h" 23 24 void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) 25 { 26 WRITE_ONCE(q->rq_timeout, timeout); 27 } 28 EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); 29 30 /** 31 * blk_set_stacking_limits - set default limits for stacking devices 32 * @lim: the queue_limits structure to reset 33 * 34 * Prepare queue limits for applying limits from underlying devices using 35 * blk_stack_limits(). 36 */ 37 void blk_set_stacking_limits(struct queue_limits *lim) 38 { 39 memset(lim, 0, sizeof(*lim)); 40 lim->logical_block_size = SECTOR_SIZE; 41 lim->physical_block_size = SECTOR_SIZE; 42 lim->io_min = SECTOR_SIZE; 43 lim->discard_granularity = SECTOR_SIZE; 44 lim->dma_alignment = SECTOR_SIZE - 1; 45 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; 46 47 /* Inherit limits from component devices */ 48 lim->max_segments = USHRT_MAX; 49 lim->max_discard_segments = USHRT_MAX; 50 lim->max_hw_sectors = UINT_MAX; 51 lim->max_segment_size = UINT_MAX; 52 lim->max_sectors = UINT_MAX; 53 lim->max_dev_sectors = UINT_MAX; 54 lim->max_write_zeroes_sectors = UINT_MAX; 55 lim->max_hw_wzeroes_unmap_sectors = UINT_MAX; 56 lim->max_user_wzeroes_unmap_sectors = UINT_MAX; 57 lim->max_hw_zone_append_sectors = UINT_MAX; 58 lim->max_user_discard_sectors = UINT_MAX; 59 lim->atomic_write_hw_max = UINT_MAX; 60 } 61 EXPORT_SYMBOL(blk_set_stacking_limits); 62 63 void blk_apply_bdi_limits(struct backing_dev_info *bdi, 64 struct queue_limits *lim) 65 { 66 u64 io_opt = lim->io_opt; 67 68 /* 69 * For read-ahead of large files to be effective, we need to read ahead 70 * at least twice the optimal I/O size. For rotational devices that do 71 * not report an optimal I/O size (e.g. ATA HDDs), use the maximum I/O 72 * size to avoid falling back to the (rather inefficient) small default 73 * read-ahead size. 74 * 75 * There is no hardware limitation for the read-ahead size and the user 76 * might have increased the read-ahead size through sysfs, so don't ever 77 * decrease it. 78 */ 79 if (!io_opt && (lim->features & BLK_FEAT_ROTATIONAL)) 80 io_opt = (u64)lim->max_sectors << SECTOR_SHIFT; 81 82 bdi->ra_pages = max3(bdi->ra_pages, 83 io_opt * 2 >> PAGE_SHIFT, 84 VM_READAHEAD_PAGES); 85 bdi->io_pages = lim->max_sectors >> PAGE_SECTORS_SHIFT; 86 } 87 88 static int blk_validate_zoned_limits(struct queue_limits *lim) 89 { 90 if (!(lim->features & BLK_FEAT_ZONED)) { 91 if (WARN_ON_ONCE(lim->max_open_zones) || 92 WARN_ON_ONCE(lim->max_active_zones) || 93 WARN_ON_ONCE(lim->zone_write_granularity) || 94 WARN_ON_ONCE(lim->max_zone_append_sectors)) 95 return -EINVAL; 96 return 0; 97 } 98 99 if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED))) 100 return -EINVAL; 101 102 /* 103 * Given that active zones include open zones, the maximum number of 104 * open zones cannot be larger than the maximum number of active zones. 105 */ 106 if (lim->max_active_zones && 107 lim->max_open_zones > lim->max_active_zones) 108 return -EINVAL; 109 110 if (lim->zone_write_granularity < lim->logical_block_size) 111 lim->zone_write_granularity = lim->logical_block_size; 112 113 /* 114 * The Zone Append size is limited by the maximum I/O size and the zone 115 * size given that it can't span zones. 116 * 117 * If no max_hw_zone_append_sectors limit is provided, the block layer 118 * will emulated it, else we're also bound by the hardware limit. 119 */ 120 lim->max_zone_append_sectors = 121 min_not_zero(lim->max_hw_zone_append_sectors, 122 min(lim->chunk_sectors, lim->max_hw_sectors)); 123 return 0; 124 } 125 126 static int blk_validate_integrity_limits(struct queue_limits *lim) 127 { 128 struct blk_integrity *bi = &lim->integrity; 129 130 if (!bi->metadata_size) { 131 if (bi->csum_type != BLK_INTEGRITY_CSUM_NONE || 132 bi->tag_size || ((bi->flags & BLK_INTEGRITY_REF_TAG))) { 133 pr_warn("invalid PI settings.\n"); 134 return -EINVAL; 135 } 136 bi->flags |= BLK_INTEGRITY_NOGENERATE | BLK_INTEGRITY_NOVERIFY; 137 return 0; 138 } 139 140 if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)) { 141 pr_warn("integrity support disabled.\n"); 142 return -EINVAL; 143 } 144 145 if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE && 146 (bi->flags & BLK_INTEGRITY_REF_TAG)) { 147 pr_warn("ref tag not support without checksum.\n"); 148 return -EINVAL; 149 } 150 151 if (bi->pi_offset + bi->pi_tuple_size > bi->metadata_size) { 152 pr_warn("pi_offset (%u) + pi_tuple_size (%u) exceeds metadata_size (%u)\n", 153 bi->pi_offset, bi->pi_tuple_size, bi->metadata_size); 154 return -EINVAL; 155 } 156 157 switch (bi->csum_type) { 158 case BLK_INTEGRITY_CSUM_NONE: 159 if (bi->pi_tuple_size) { 160 pr_warn("pi_tuple_size must be 0 when checksum type is none\n"); 161 return -EINVAL; 162 } 163 break; 164 case BLK_INTEGRITY_CSUM_CRC: 165 case BLK_INTEGRITY_CSUM_IP: 166 if (bi->pi_tuple_size != sizeof(struct t10_pi_tuple)) { 167 pr_warn("pi_tuple_size mismatch for T10 PI: expected %zu, got %u\n", 168 sizeof(struct t10_pi_tuple), 169 bi->pi_tuple_size); 170 return -EINVAL; 171 } 172 break; 173 case BLK_INTEGRITY_CSUM_CRC64: 174 if (bi->pi_tuple_size != sizeof(struct crc64_pi_tuple)) { 175 pr_warn("pi_tuple_size mismatch for CRC64 PI: expected %zu, got %u\n", 176 sizeof(struct crc64_pi_tuple), 177 bi->pi_tuple_size); 178 return -EINVAL; 179 } 180 break; 181 } 182 183 if (!bi->interval_exp) { 184 bi->interval_exp = ilog2(lim->logical_block_size); 185 } else if (bi->interval_exp < SECTOR_SHIFT || 186 bi->interval_exp > ilog2(lim->logical_block_size)) { 187 pr_warn("invalid interval_exp %u\n", bi->interval_exp); 188 return -EINVAL; 189 } 190 191 /* 192 * Some IO controllers can not handle data intervals straddling 193 * multiple bio_vecs. For those, enforce alignment so that those are 194 * never generated, and that each buffer is aligned as expected. 195 */ 196 if (!(bi->flags & BLK_SPLIT_INTERVAL_CAPABLE) && bi->csum_type) { 197 lim->dma_alignment = max(lim->dma_alignment, 198 (1U << bi->interval_exp) - 1); 199 } 200 201 /* 202 * The block layer automatically adds integrity data for bios that don't 203 * already have it. Limit the I/O size so that a single maximum size 204 * metadata segment can cover the integrity data for the entire I/O. 205 */ 206 lim->max_sectors = min(lim->max_sectors, 207 max_integrity_io_size(lim) >> SECTOR_SHIFT); 208 209 return 0; 210 } 211 212 /* 213 * Returns max guaranteed bytes which we can fit in a bio. 214 * 215 * We request that an atomic_write is ITER_UBUF iov_iter (so a single vector), 216 * so we assume that we can fit in at least PAGE_SIZE in a segment, apart from 217 * the first and last segments. 218 */ 219 static unsigned int blk_queue_max_guaranteed_bio(struct queue_limits *lim) 220 { 221 unsigned int max_segments = min(BIO_MAX_VECS, lim->max_segments); 222 unsigned int length; 223 224 length = min(max_segments, 2) * lim->logical_block_size; 225 if (max_segments > 2) 226 length += (max_segments - 2) * PAGE_SIZE; 227 228 return length; 229 } 230 231 static void blk_atomic_writes_update_limits(struct queue_limits *lim) 232 { 233 unsigned int unit_limit = min(lim->max_hw_sectors << SECTOR_SHIFT, 234 blk_queue_max_guaranteed_bio(lim)); 235 236 unit_limit = rounddown_pow_of_two(unit_limit); 237 238 lim->atomic_write_max_sectors = 239 min(lim->atomic_write_hw_max >> SECTOR_SHIFT, 240 lim->max_hw_sectors); 241 lim->atomic_write_unit_min = 242 min(lim->atomic_write_hw_unit_min, unit_limit); 243 lim->atomic_write_unit_max = 244 min(lim->atomic_write_hw_unit_max, unit_limit); 245 lim->atomic_write_boundary_sectors = 246 lim->atomic_write_hw_boundary >> SECTOR_SHIFT; 247 } 248 249 /* 250 * Test whether any boundary is aligned with any chunk size. Stacked 251 * devices store any stripe size in t->chunk_sectors. 252 */ 253 static bool blk_valid_atomic_writes_boundary(unsigned int chunk_sectors, 254 unsigned int boundary_sectors) 255 { 256 if (!chunk_sectors || !boundary_sectors) 257 return true; 258 259 if (boundary_sectors > chunk_sectors && 260 boundary_sectors % chunk_sectors) 261 return false; 262 263 if (chunk_sectors > boundary_sectors && 264 chunk_sectors % boundary_sectors) 265 return false; 266 267 return true; 268 } 269 270 static void blk_validate_atomic_write_limits(struct queue_limits *lim) 271 { 272 unsigned int boundary_sectors; 273 unsigned int atomic_write_hw_max_sectors = 274 lim->atomic_write_hw_max >> SECTOR_SHIFT; 275 276 if (!(lim->features & BLK_FEAT_ATOMIC_WRITES)) 277 goto unsupported; 278 279 /* UINT_MAX indicates stacked limits in initial state */ 280 if (lim->atomic_write_hw_max == UINT_MAX) 281 goto unsupported; 282 283 if (!lim->atomic_write_hw_max) 284 goto unsupported; 285 286 if (WARN_ON_ONCE(!is_power_of_2(lim->atomic_write_hw_unit_min))) 287 goto unsupported; 288 289 if (WARN_ON_ONCE(!is_power_of_2(lim->atomic_write_hw_unit_max))) 290 goto unsupported; 291 292 if (WARN_ON_ONCE(lim->atomic_write_hw_unit_min > 293 lim->atomic_write_hw_unit_max)) 294 goto unsupported; 295 296 if (WARN_ON_ONCE(lim->atomic_write_hw_unit_max > 297 lim->atomic_write_hw_max)) 298 goto unsupported; 299 300 if (WARN_ON_ONCE(lim->chunk_sectors && 301 atomic_write_hw_max_sectors > lim->chunk_sectors)) 302 goto unsupported; 303 304 boundary_sectors = lim->atomic_write_hw_boundary >> SECTOR_SHIFT; 305 306 if (boundary_sectors) { 307 if (WARN_ON_ONCE(lim->atomic_write_hw_max > 308 lim->atomic_write_hw_boundary)) 309 goto unsupported; 310 311 if (WARN_ON_ONCE(!blk_valid_atomic_writes_boundary( 312 lim->chunk_sectors, boundary_sectors))) 313 goto unsupported; 314 315 /* 316 * The boundary size just needs to be a multiple of unit_max 317 * (and not necessarily a power-of-2), so this following check 318 * could be relaxed in future. 319 * Furthermore, if needed, unit_max could even be reduced so 320 * that it is compliant with a !power-of-2 boundary. 321 */ 322 if (!is_power_of_2(boundary_sectors)) 323 goto unsupported; 324 } 325 326 blk_atomic_writes_update_limits(lim); 327 return; 328 329 unsupported: 330 lim->atomic_write_max_sectors = 0; 331 lim->atomic_write_boundary_sectors = 0; 332 lim->atomic_write_unit_min = 0; 333 lim->atomic_write_unit_max = 0; 334 } 335 336 /* 337 * Check that the limits in lim are valid, initialize defaults for unset 338 * values, and cap values based on others where needed. 339 */ 340 int blk_validate_limits(struct queue_limits *lim) 341 { 342 unsigned int max_hw_sectors; 343 unsigned int logical_block_sectors; 344 unsigned long seg_size; 345 int err; 346 347 /* 348 * Unless otherwise specified, default to 512 byte logical blocks and a 349 * physical block size equal to the logical block size. 350 */ 351 if (!lim->logical_block_size) 352 lim->logical_block_size = SECTOR_SIZE; 353 else if (blk_validate_block_size(lim->logical_block_size)) { 354 pr_warn("Invalid logical block size (%d)\n", lim->logical_block_size); 355 return -EINVAL; 356 } 357 if (lim->physical_block_size < lim->logical_block_size) { 358 lim->physical_block_size = lim->logical_block_size; 359 } else if (!is_power_of_2(lim->physical_block_size)) { 360 pr_warn("Invalid physical block size (%d)\n", lim->physical_block_size); 361 return -EINVAL; 362 } 363 364 /* 365 * The minimum I/O size defaults to the physical block size unless 366 * explicitly overridden. 367 */ 368 if (lim->io_min < lim->physical_block_size) 369 lim->io_min = lim->physical_block_size; 370 371 /* 372 * The optimal I/O size may not be aligned to physical block size 373 * (because it may be limited by dma engines which have no clue about 374 * block size of the disks attached to them), so we round it down here. 375 */ 376 lim->io_opt = round_down(lim->io_opt, lim->physical_block_size); 377 378 /* 379 * max_hw_sectors has a somewhat weird default for historical reason, 380 * but driver really should set their own instead of relying on this 381 * value. 382 * 383 * The block layer relies on the fact that every driver can 384 * handle at lest a page worth of data per I/O, and needs the value 385 * aligned to the logical block size. 386 */ 387 if (!lim->max_hw_sectors) 388 lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; 389 if (WARN_ON_ONCE(lim->max_hw_sectors < PAGE_SECTORS)) 390 return -EINVAL; 391 logical_block_sectors = lim->logical_block_size >> SECTOR_SHIFT; 392 if (WARN_ON_ONCE(logical_block_sectors > lim->max_hw_sectors)) 393 return -EINVAL; 394 lim->max_hw_sectors = round_down(lim->max_hw_sectors, 395 logical_block_sectors); 396 397 /* 398 * The actual max_sectors value is a complex beast and also takes the 399 * max_dev_sectors value (set by SCSI ULPs) and a user configurable 400 * value into account. The ->max_sectors value is always calculated 401 * from these, so directly setting it won't have any effect. 402 */ 403 max_hw_sectors = min_not_zero(lim->max_hw_sectors, 404 lim->max_dev_sectors); 405 if (lim->max_user_sectors) { 406 if (lim->max_user_sectors < BLK_MIN_SEGMENT_SIZE / SECTOR_SIZE) 407 return -EINVAL; 408 lim->max_sectors = min(max_hw_sectors, lim->max_user_sectors); 409 } else if (lim->io_opt > (BLK_DEF_MAX_SECTORS_CAP << SECTOR_SHIFT)) { 410 lim->max_sectors = 411 min(max_hw_sectors, lim->io_opt >> SECTOR_SHIFT); 412 } else if (lim->io_min > (BLK_DEF_MAX_SECTORS_CAP << SECTOR_SHIFT)) { 413 lim->max_sectors = 414 min(max_hw_sectors, lim->io_min >> SECTOR_SHIFT); 415 } else { 416 lim->max_sectors = min(max_hw_sectors, BLK_DEF_MAX_SECTORS_CAP); 417 } 418 lim->max_sectors = round_down(lim->max_sectors, 419 logical_block_sectors); 420 421 /* 422 * Random default for the maximum number of segments. Driver should not 423 * rely on this and set their own. 424 */ 425 if (!lim->max_segments) 426 lim->max_segments = BLK_MAX_SEGMENTS; 427 428 if (lim->max_hw_wzeroes_unmap_sectors && 429 lim->max_hw_wzeroes_unmap_sectors != lim->max_write_zeroes_sectors) 430 return -EINVAL; 431 lim->max_wzeroes_unmap_sectors = min(lim->max_hw_wzeroes_unmap_sectors, 432 lim->max_user_wzeroes_unmap_sectors); 433 434 lim->max_discard_sectors = 435 min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors); 436 437 /* 438 * When discard is not supported, discard_granularity should be reported 439 * as 0 to userspace. 440 */ 441 if (lim->max_discard_sectors) 442 lim->discard_granularity = 443 max(lim->discard_granularity, lim->physical_block_size); 444 else 445 lim->discard_granularity = 0; 446 447 if (!lim->max_discard_segments) 448 lim->max_discard_segments = 1; 449 450 /* 451 * By default there is no limit on the segment boundary alignment, 452 * but if there is one it can't be smaller than the page size as 453 * that would break all the normal I/O patterns. 454 */ 455 if (!lim->seg_boundary_mask) 456 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; 457 if (WARN_ON_ONCE(lim->seg_boundary_mask < BLK_MIN_SEGMENT_SIZE - 1)) 458 return -EINVAL; 459 460 /* 461 * Stacking device may have both virtual boundary and max segment 462 * size limit, so allow this setting now, and long-term the two 463 * might need to move out of stacking limits since we have immutable 464 * bvec and lower layer bio splitting is supposed to handle the two 465 * correctly. 466 */ 467 if (lim->virt_boundary_mask) { 468 if (!lim->max_segment_size) 469 lim->max_segment_size = UINT_MAX; 470 } else { 471 /* 472 * The maximum segment size has an odd historic 64k default that 473 * drivers probably should override. Just like the I/O size we 474 * require drivers to at least handle a full page per segment. 475 */ 476 if (!lim->max_segment_size) 477 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; 478 if (WARN_ON_ONCE(lim->max_segment_size < BLK_MIN_SEGMENT_SIZE)) 479 return -EINVAL; 480 } 481 482 /* setup max segment size for building new segment in fast path */ 483 if (lim->seg_boundary_mask > lim->max_segment_size - 1) 484 seg_size = lim->max_segment_size; 485 else 486 seg_size = lim->seg_boundary_mask + 1; 487 lim->max_fast_segment_size = min_t(unsigned int, seg_size, PAGE_SIZE); 488 489 /* 490 * We require drivers to at least do logical block aligned I/O, but 491 * historically could not check for that due to the separate calls 492 * to set the limits. Once the transition is finished the check 493 * below should be narrowed down to check the logical block size. 494 */ 495 if (!lim->dma_alignment) 496 lim->dma_alignment = SECTOR_SIZE - 1; 497 if (WARN_ON_ONCE(lim->dma_alignment > PAGE_SIZE)) 498 return -EINVAL; 499 500 if (lim->alignment_offset) { 501 lim->alignment_offset &= (lim->physical_block_size - 1); 502 lim->flags &= ~BLK_FLAG_MISALIGNED; 503 } 504 505 if (!(lim->features & BLK_FEAT_WRITE_CACHE)) 506 lim->features &= ~BLK_FEAT_FUA; 507 508 blk_validate_atomic_write_limits(lim); 509 510 err = blk_validate_integrity_limits(lim); 511 if (err) 512 return err; 513 return blk_validate_zoned_limits(lim); 514 } 515 EXPORT_SYMBOL_GPL(blk_validate_limits); 516 517 /* 518 * Set the default limits for a newly allocated queue. @lim contains the 519 * initial limits set by the driver, which could be no limit in which case 520 * all fields are cleared to zero. 521 */ 522 int blk_set_default_limits(struct queue_limits *lim) 523 { 524 /* 525 * Most defaults are set by capping the bounds in blk_validate_limits, 526 * but these limits are special and need an explicit initialization to 527 * the max value here. 528 */ 529 lim->max_user_discard_sectors = UINT_MAX; 530 lim->max_user_wzeroes_unmap_sectors = UINT_MAX; 531 return blk_validate_limits(lim); 532 } 533 534 /** 535 * queue_limits_commit_update - commit an atomic update of queue limits 536 * @q: queue to update 537 * @lim: limits to apply 538 * 539 * Apply the limits in @lim that were obtained from queue_limits_start_update() 540 * and updated by the caller to @q. The caller must have frozen the queue or 541 * ensure that there are no outstanding I/Os by other means. 542 * 543 * Returns 0 if successful, else a negative error code. 544 */ 545 int queue_limits_commit_update(struct request_queue *q, 546 struct queue_limits *lim) 547 { 548 int error; 549 550 lockdep_assert_held(&q->limits_lock); 551 552 error = blk_validate_limits(lim); 553 if (error) 554 goto out_unlock; 555 556 #ifdef CONFIG_BLK_INLINE_ENCRYPTION 557 if (q->crypto_profile && lim->integrity.tag_size) { 558 pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together.\n"); 559 error = -EINVAL; 560 goto out_unlock; 561 } 562 #endif 563 564 q->limits = *lim; 565 if (q->disk) 566 blk_apply_bdi_limits(q->disk->bdi, lim); 567 out_unlock: 568 mutex_unlock(&q->limits_lock); 569 return error; 570 } 571 EXPORT_SYMBOL_GPL(queue_limits_commit_update); 572 573 /** 574 * queue_limits_commit_update_frozen - commit an atomic update of queue limits 575 * @q: queue to update 576 * @lim: limits to apply 577 * 578 * Apply the limits in @lim that were obtained from queue_limits_start_update() 579 * and updated with the new values by the caller to @q. Freezes the queue 580 * before the update and unfreezes it after. 581 * 582 * Returns 0 if successful, else a negative error code. 583 */ 584 int queue_limits_commit_update_frozen(struct request_queue *q, 585 struct queue_limits *lim) 586 { 587 unsigned int memflags; 588 int ret; 589 590 memflags = blk_mq_freeze_queue(q); 591 ret = queue_limits_commit_update(q, lim); 592 blk_mq_unfreeze_queue(q, memflags); 593 594 return ret; 595 } 596 EXPORT_SYMBOL_GPL(queue_limits_commit_update_frozen); 597 598 /** 599 * queue_limits_set - apply queue limits to queue 600 * @q: queue to update 601 * @lim: limits to apply 602 * 603 * Apply the limits in @lim that were freshly initialized to @q. 604 * To update existing limits use queue_limits_start_update() and 605 * queue_limits_commit_update() instead. 606 * 607 * Returns 0 if successful, else a negative error code. 608 */ 609 int queue_limits_set(struct request_queue *q, struct queue_limits *lim) 610 { 611 mutex_lock(&q->limits_lock); 612 return queue_limits_commit_update(q, lim); 613 } 614 EXPORT_SYMBOL_GPL(queue_limits_set); 615 616 static int queue_limit_alignment_offset(const struct queue_limits *lim, 617 sector_t sector) 618 { 619 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 620 unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT) 621 << SECTOR_SHIFT; 622 623 return (granularity + lim->alignment_offset - alignment) % granularity; 624 } 625 626 static unsigned int queue_limit_discard_alignment( 627 const struct queue_limits *lim, sector_t sector) 628 { 629 unsigned int alignment, granularity, offset; 630 631 if (!lim->max_discard_sectors) 632 return 0; 633 634 /* Why are these in bytes, not sectors? */ 635 alignment = lim->discard_alignment >> SECTOR_SHIFT; 636 granularity = lim->discard_granularity >> SECTOR_SHIFT; 637 638 /* Offset of the partition start in 'granularity' sectors */ 639 offset = sector_div(sector, granularity); 640 641 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 642 offset = (granularity + alignment - offset) % granularity; 643 644 /* Turn it back into bytes, gaah */ 645 return offset << SECTOR_SHIFT; 646 } 647 648 static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs) 649 { 650 sectors = round_down(sectors, lbs >> SECTOR_SHIFT); 651 if (sectors < PAGE_SIZE >> SECTOR_SHIFT) 652 sectors = PAGE_SIZE >> SECTOR_SHIFT; 653 return sectors; 654 } 655 656 /* Check if second and later bottom devices are compliant */ 657 static bool blk_stack_atomic_writes_tail(struct queue_limits *t, 658 struct queue_limits *b) 659 { 660 /* We're not going to support different boundary sizes.. yet */ 661 if (t->atomic_write_hw_boundary != b->atomic_write_hw_boundary) 662 return false; 663 664 /* Can't support this */ 665 if (t->atomic_write_hw_unit_min > b->atomic_write_hw_unit_max) 666 return false; 667 668 /* Or this */ 669 if (t->atomic_write_hw_unit_max < b->atomic_write_hw_unit_min) 670 return false; 671 672 t->atomic_write_hw_max = min(t->atomic_write_hw_max, 673 b->atomic_write_hw_max); 674 t->atomic_write_hw_unit_min = max(t->atomic_write_hw_unit_min, 675 b->atomic_write_hw_unit_min); 676 t->atomic_write_hw_unit_max = min(t->atomic_write_hw_unit_max, 677 b->atomic_write_hw_unit_max); 678 return true; 679 } 680 681 static void blk_stack_atomic_writes_chunk_sectors(struct queue_limits *t) 682 { 683 unsigned int chunk_bytes; 684 685 if (!t->chunk_sectors) 686 return; 687 688 /* 689 * If chunk sectors is so large that its value in bytes overflows 690 * UINT_MAX, then just shift it down so it definitely will fit. 691 * We don't support atomic writes of such a large size anyway. 692 */ 693 if (check_shl_overflow(t->chunk_sectors, SECTOR_SHIFT, &chunk_bytes)) 694 chunk_bytes = t->chunk_sectors; 695 696 /* 697 * Find values for limits which work for chunk size. 698 * b->atomic_write_hw_unit_{min, max} may not be aligned with chunk 699 * size, as the chunk size is not restricted to a power-of-2. 700 * So we need to find highest power-of-2 which works for the chunk 701 * size. 702 * As an example scenario, we could have t->unit_max = 16K and 703 * t->chunk_sectors = 24KB. For this case, reduce t->unit_max to a 704 * value aligned with both limits, i.e. 8K in this example. 705 */ 706 t->atomic_write_hw_unit_max = min(t->atomic_write_hw_unit_max, 707 max_pow_of_two_factor(chunk_bytes)); 708 709 t->atomic_write_hw_unit_min = min(t->atomic_write_hw_unit_min, 710 t->atomic_write_hw_unit_max); 711 t->atomic_write_hw_max = min(t->atomic_write_hw_max, chunk_bytes); 712 } 713 714 /* Check stacking of first bottom device */ 715 static bool blk_stack_atomic_writes_head(struct queue_limits *t, 716 struct queue_limits *b) 717 { 718 if (!blk_valid_atomic_writes_boundary(t->chunk_sectors, 719 b->atomic_write_hw_boundary >> SECTOR_SHIFT)) 720 return false; 721 722 t->atomic_write_hw_unit_max = b->atomic_write_hw_unit_max; 723 t->atomic_write_hw_unit_min = b->atomic_write_hw_unit_min; 724 t->atomic_write_hw_max = b->atomic_write_hw_max; 725 t->atomic_write_hw_boundary = b->atomic_write_hw_boundary; 726 return true; 727 } 728 729 static void blk_stack_atomic_writes_limits(struct queue_limits *t, 730 struct queue_limits *b, sector_t start) 731 { 732 if (!(b->features & BLK_FEAT_ATOMIC_WRITES)) 733 goto unsupported; 734 735 if (!b->atomic_write_hw_unit_min) 736 goto unsupported; 737 738 if (!blk_atomic_write_start_sect_aligned(start, b)) 739 goto unsupported; 740 741 /* UINT_MAX indicates no stacking of bottom devices yet */ 742 if (t->atomic_write_hw_max == UINT_MAX) { 743 if (!blk_stack_atomic_writes_head(t, b)) 744 goto unsupported; 745 } else { 746 if (!blk_stack_atomic_writes_tail(t, b)) 747 goto unsupported; 748 } 749 blk_stack_atomic_writes_chunk_sectors(t); 750 return; 751 752 unsupported: 753 t->atomic_write_hw_max = 0; 754 t->atomic_write_hw_unit_max = 0; 755 t->atomic_write_hw_unit_min = 0; 756 t->atomic_write_hw_boundary = 0; 757 } 758 759 /** 760 * blk_stack_limits - adjust queue_limits for stacked devices 761 * @t: the stacking driver limits (top device) 762 * @b: the underlying queue limits (bottom, component device) 763 * @start: first data sector within component device 764 * 765 * Description: 766 * This function is used by stacking drivers like MD and DM to ensure 767 * that all component devices have compatible block sizes and 768 * alignments. The stacking driver must provide a queue_limits 769 * struct (top) and then iteratively call the stacking function for 770 * all component (bottom) devices. The stacking function will 771 * attempt to combine the values and ensure proper alignment. 772 * 773 * Returns 0 if the top and bottom queue_limits are compatible. The 774 * top device's block sizes and alignment offsets may be adjusted to 775 * ensure alignment with the bottom device. If no compatible sizes 776 * and alignments exist, -1 is returned and the resulting top 777 * queue_limits will have the misaligned flag set to indicate that 778 * the alignment_offset is undefined. 779 */ 780 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 781 sector_t start) 782 { 783 unsigned int top, bottom, alignment; 784 int ret = 0; 785 786 t->features |= (b->features & BLK_FEAT_INHERIT_MASK); 787 788 /* 789 * Some feaures need to be supported both by the stacking driver and all 790 * underlying devices. The stacking driver sets these flags before 791 * stacking the limits, and this will clear the flags if any of the 792 * underlying devices does not support it. 793 */ 794 if (!(b->features & BLK_FEAT_NOWAIT)) 795 t->features &= ~BLK_FEAT_NOWAIT; 796 if (!(b->features & BLK_FEAT_POLL)) 797 t->features &= ~BLK_FEAT_POLL; 798 799 t->flags |= (b->flags & BLK_FLAG_MISALIGNED); 800 801 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); 802 t->max_user_sectors = min_not_zero(t->max_user_sectors, 803 b->max_user_sectors); 804 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); 805 t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors); 806 t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors, 807 b->max_write_zeroes_sectors); 808 t->max_user_wzeroes_unmap_sectors = 809 min(t->max_user_wzeroes_unmap_sectors, 810 b->max_user_wzeroes_unmap_sectors); 811 t->max_hw_wzeroes_unmap_sectors = 812 min(t->max_hw_wzeroes_unmap_sectors, 813 b->max_hw_wzeroes_unmap_sectors); 814 815 t->max_hw_zone_append_sectors = min(t->max_hw_zone_append_sectors, 816 b->max_hw_zone_append_sectors); 817 818 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, 819 b->seg_boundary_mask); 820 t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask, 821 b->virt_boundary_mask); 822 823 t->max_segments = min_not_zero(t->max_segments, b->max_segments); 824 t->max_discard_segments = min_not_zero(t->max_discard_segments, 825 b->max_discard_segments); 826 t->max_integrity_segments = min_not_zero(t->max_integrity_segments, 827 b->max_integrity_segments); 828 829 t->max_segment_size = min_not_zero(t->max_segment_size, 830 b->max_segment_size); 831 832 alignment = queue_limit_alignment_offset(b, start); 833 834 /* Bottom device has different alignment. Check that it is 835 * compatible with the current top alignment. 836 */ 837 if (t->alignment_offset != alignment) { 838 839 top = max(t->physical_block_size, t->io_min) 840 + t->alignment_offset; 841 bottom = max(b->physical_block_size, b->io_min) + alignment; 842 843 /* Verify that top and bottom intervals line up */ 844 if (max(top, bottom) % min(top, bottom)) { 845 t->flags |= BLK_FLAG_MISALIGNED; 846 ret = -1; 847 } 848 } 849 850 t->logical_block_size = max(t->logical_block_size, 851 b->logical_block_size); 852 853 t->physical_block_size = max(t->physical_block_size, 854 b->physical_block_size); 855 856 t->io_min = max(t->io_min, b->io_min); 857 t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); 858 t->dma_alignment = max(t->dma_alignment, b->dma_alignment); 859 860 /* Set non-power-of-2 compatible chunk_sectors boundary */ 861 if (b->chunk_sectors) 862 t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors); 863 864 /* Physical block size a multiple of the logical block size? */ 865 if (t->physical_block_size & (t->logical_block_size - 1)) { 866 t->physical_block_size = t->logical_block_size; 867 t->flags |= BLK_FLAG_MISALIGNED; 868 ret = -1; 869 } 870 871 /* Minimum I/O a multiple of the physical block size? */ 872 if (t->io_min & (t->physical_block_size - 1)) { 873 t->io_min = t->physical_block_size; 874 t->flags |= BLK_FLAG_MISALIGNED; 875 ret = -1; 876 } 877 878 /* Optimal I/O a multiple of the physical block size? */ 879 if (t->io_opt & (t->physical_block_size - 1)) { 880 t->io_opt = 0; 881 t->flags |= BLK_FLAG_MISALIGNED; 882 ret = -1; 883 } 884 885 /* chunk_sectors a multiple of the physical block size? */ 886 if (t->chunk_sectors % (t->physical_block_size >> SECTOR_SHIFT)) { 887 t->chunk_sectors = 0; 888 t->flags |= BLK_FLAG_MISALIGNED; 889 ret = -1; 890 } 891 892 /* Find lowest common alignment_offset */ 893 t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment) 894 % max(t->physical_block_size, t->io_min); 895 896 /* Verify that new alignment_offset is on a logical block boundary */ 897 if (t->alignment_offset & (t->logical_block_size - 1)) { 898 t->flags |= BLK_FLAG_MISALIGNED; 899 ret = -1; 900 } 901 902 t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size); 903 t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size); 904 t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size); 905 906 /* Discard alignment and granularity */ 907 if (b->discard_granularity) { 908 alignment = queue_limit_discard_alignment(b, start); 909 910 t->max_discard_sectors = min_not_zero(t->max_discard_sectors, 911 b->max_discard_sectors); 912 t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors, 913 b->max_hw_discard_sectors); 914 t->discard_granularity = max(t->discard_granularity, 915 b->discard_granularity); 916 t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) % 917 t->discard_granularity; 918 } 919 t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors, 920 b->max_secure_erase_sectors); 921 t->zone_write_granularity = max(t->zone_write_granularity, 922 b->zone_write_granularity); 923 if (!(t->features & BLK_FEAT_ZONED)) { 924 t->zone_write_granularity = 0; 925 t->max_zone_append_sectors = 0; 926 } 927 blk_stack_atomic_writes_limits(t, b, start); 928 929 return ret; 930 } 931 EXPORT_SYMBOL(blk_stack_limits); 932 933 /** 934 * queue_limits_stack_bdev - adjust queue_limits for stacked devices 935 * @t: the stacking driver limits (top device) 936 * @bdev: the underlying block device (bottom) 937 * @offset: offset to beginning of data within component device 938 * @pfx: prefix to use for warnings logged 939 * 940 * Description: 941 * This function is used by stacking drivers like MD and DM to ensure 942 * that all component devices have compatible block sizes and 943 * alignments. The stacking driver must provide a queue_limits 944 * struct (top) and then iteratively call the stacking function for 945 * all component (bottom) devices. The stacking function will 946 * attempt to combine the values and ensure proper alignment. 947 */ 948 void queue_limits_stack_bdev(struct queue_limits *t, struct block_device *bdev, 949 sector_t offset, const char *pfx) 950 { 951 if (blk_stack_limits(t, bdev_limits(bdev), 952 get_start_sect(bdev) + offset)) 953 pr_notice("%s: Warning: Device %pg is misaligned\n", 954 pfx, bdev); 955 } 956 EXPORT_SYMBOL_GPL(queue_limits_stack_bdev); 957 958 /** 959 * queue_limits_stack_integrity - stack integrity profile 960 * @t: target queue limits 961 * @b: base queue limits 962 * 963 * Check if the integrity profile in the @b can be stacked into the 964 * target @t. Stacking is possible if either: 965 * 966 * a) does not have any integrity information stacked into it yet 967 * b) the integrity profile in @b is identical to the one in @t 968 * 969 * If @b can be stacked into @t, return %true. Else return %false and clear the 970 * integrity information in @t. 971 */ 972 bool queue_limits_stack_integrity(struct queue_limits *t, 973 struct queue_limits *b) 974 { 975 struct blk_integrity *ti = &t->integrity; 976 struct blk_integrity *bi = &b->integrity; 977 978 if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)) 979 return true; 980 981 if (ti->flags & BLK_INTEGRITY_STACKED) { 982 if (ti->metadata_size != bi->metadata_size) 983 goto incompatible; 984 if (ti->interval_exp != bi->interval_exp) 985 goto incompatible; 986 if (ti->tag_size != bi->tag_size) 987 goto incompatible; 988 if (ti->csum_type != bi->csum_type) 989 goto incompatible; 990 if (ti->pi_tuple_size != bi->pi_tuple_size) 991 goto incompatible; 992 if ((ti->flags & BLK_INTEGRITY_REF_TAG) != 993 (bi->flags & BLK_INTEGRITY_REF_TAG)) 994 goto incompatible; 995 if ((ti->flags & BLK_SPLIT_INTERVAL_CAPABLE) && 996 !(bi->flags & BLK_SPLIT_INTERVAL_CAPABLE)) 997 ti->flags &= ~BLK_SPLIT_INTERVAL_CAPABLE; 998 } else { 999 ti->flags = BLK_INTEGRITY_STACKED; 1000 ti->flags |= (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) | 1001 (bi->flags & BLK_INTEGRITY_REF_TAG) | 1002 (bi->flags & BLK_SPLIT_INTERVAL_CAPABLE); 1003 ti->csum_type = bi->csum_type; 1004 ti->pi_tuple_size = bi->pi_tuple_size; 1005 ti->metadata_size = bi->metadata_size; 1006 ti->pi_offset = bi->pi_offset; 1007 ti->interval_exp = bi->interval_exp; 1008 ti->tag_size = bi->tag_size; 1009 } 1010 return true; 1011 1012 incompatible: 1013 memset(ti, 0, sizeof(*ti)); 1014 return false; 1015 } 1016 EXPORT_SYMBOL_GPL(queue_limits_stack_integrity); 1017 1018 /** 1019 * blk_set_queue_depth - tell the block layer about the device queue depth 1020 * @q: the request queue for the device 1021 * @depth: queue depth 1022 * 1023 */ 1024 void blk_set_queue_depth(struct request_queue *q, unsigned int depth) 1025 { 1026 q->queue_depth = depth; 1027 rq_qos_queue_depth_changed(q); 1028 } 1029 EXPORT_SYMBOL(blk_set_queue_depth); 1030 1031 int bdev_alignment_offset(struct block_device *bdev) 1032 { 1033 struct request_queue *q = bdev_get_queue(bdev); 1034 1035 if (q->limits.flags & BLK_FLAG_MISALIGNED) 1036 return -1; 1037 if (bdev_is_partition(bdev)) 1038 return queue_limit_alignment_offset(&q->limits, 1039 bdev->bd_start_sect); 1040 return q->limits.alignment_offset; 1041 } 1042 EXPORT_SYMBOL_GPL(bdev_alignment_offset); 1043 1044 unsigned int bdev_discard_alignment(struct block_device *bdev) 1045 { 1046 struct request_queue *q = bdev_get_queue(bdev); 1047 1048 if (bdev_is_partition(bdev)) 1049 return queue_limit_discard_alignment(&q->limits, 1050 bdev->bd_start_sect); 1051 return q->limits.discard_alignment; 1052 } 1053 EXPORT_SYMBOL_GPL(bdev_discard_alignment); 1054